It is well known that many vehicles, including motorcycles, snowmobiles, all-terrain vehicles, watercraft, and the like, are powered by internal combustion engines. Typically, these engines are positioned within engine compartments and are adapted to propel the vehicles. Generally, each internal combustion engine communicates with a cooling system that functions to cool the engine. If the engine is liquid cooled, the cooling system generally will include one or more heat exchangers (e.g., extruded radiators). These heat exchangers are typically spaced away from the engine and are used for running engine coolant therethrough for heat dissipation purposes, as is known in the art. Generally, these heat exchangers are linked to the engine through passages (e.g., rubber hoses) operatively coupled to the engine.
In snowmobiles, the heat exchangers are generally positioned within the snowmobile drive tunnel (generally located beneath a rear body portion of the snowmobile). An endless drive track, also disposed within the drive tunnel, carries and circulates snow within the drive tunnel as the track moves. The heat exchangers are positioned adjacent to the track so that some of the snow carried by the track is subsequently deposited onto the heat exchangers. Generally, the coolant running from the engine is of an elevated temperature. As such, when circulated through the heat exchanger, the coolant causes outer surfaces of the heat exchanger to rise in temperature. Subsequently, if cool air makes contact with the heat exchanger, the air will likely cause the heat exchanger outer surfaces to lower in temperature, thereby also lowering the temperature of the engine coolant circulating therein as well. Alternatively, if snow makes contact with the heat exchanger, it will likely melt because of the high temperature outer surfaces of the heat exchanger. The melting of the snow requires a substantial amount of heat, which is essentially removed from the heat exchanger and the engine coolant therein.
Engine cooling problems can occur with snowmobiles, however, when used in low snow or tightly-packed snow conditions (e.g., on a road), from which little or no snow is kicked up onto the heat exchangers in the tunnel. Thus, in many snowmobile designs, the heat exchangers within the snowmobile drive tunnel are used in combination with one or more additional heat exchangers positioned in a front portion of the snowmobile, generally within a body assembly. These heat exchangers, typically located forward of the tunnel and within the body assembly, communicate with one or more openings in the body assembly (i.e., in the hood). In turn, these heat exchangers provide heat exchange between the engine coolant circulated therein and air or airborne precipitation (e.g., snow, water, etc.) that enters the snowmobile through the openings. In turn, the engine may be adequately cooled using these heat exchangers in combination.
Unfortunately, problems are known to exist in using heat exchangers in the body assembly as described above. One such problem is the heat exchanger's potential of providing the snowmobile with a higher center of mass. As mentioned above, the heat exchanger is generally located proximate to one or more openings in the body assembly. By locating the heat exchanger proximate to the openings, the heat exchanger, in turn, is positioned relatively high in the body assembly. In turn, the snowmobile's center of mass is raised, which can likely affect the overall stability of the snowmobile. Consequently, when ridden, the snowmobile may be limited, for example, in its handling or maneuverability, which could lead to consumers having a negative impression of the snowmobile.
Another problem with such a system is the heat exchanger's potential to create steam. As mentioned above, these heat exchangers are located within the body assembly, proximate to the openings in the body assembly. As airborne precipitation (snow, water, etc.) enters the openings, it comes in contact with the heat exchanger. Contact between the high temperature outer surface of the heat exchanger and the lower temperature precipitation generally leads to the precipitation vaporizing into steam. Such steam subsequently rises out of the body assembly through the openings in the hood. As soon as the steam exits the hood, it generally condenses due to the cold outside air temperature. Subsequently, the condensation is directed at the windshield of the snowmobile by the natural flow of the air into and about the outer surface of the snowmobile. Likewise, such condensation is directed at the operator of the snowmobile. If exposed to freezing air temperatures, the condensation may additionally freeze. This condensation, being directed at and potentially freezing to the windshield and the operator, can be a nuisance for the operator in operating the snowmobile.